Mark Cavendish acknowledged today that he will face a different kind of challenge next year as he attempts to win the green jersey awarded to the best sprinter in the Tour de France, after the organisers announced radical changes to the number of points on offer at intermediate sprints on the flat stages of the 2011 race.

The Manxman missed out narrowly on the green jersey both this year and last even though he was by far the fastest sprinter in the race.

Next year the flat stages of the Tour will have only one intermediate sprint as opposed to the customary three but this single sprint will carry half the points available for the stage winner, with points awarded down to 15th place. The organisers' objective in making the change is to put an end to the somewhat formulaic scenario which is seen in most flat stages of the race, in which an escape is given leeway by the teams of sprinters such as Cavendish, then roped in close to the finish.

No one is quite certain what the new system will mean in terms of tactics for the sprinters. Cavendish said today: "We've got to sit down and evaluate it properly. I've only known about the changes for 10 minutes. We'll sit down and look at it and see if it's good or bad. It might be brilliant, it might be awful."

His team manager, Allan Peiper, said: "It's going to be interesting but whether it's to our advantage remains to be seen."

The organisers have also tweaked the points on offer for the King of the Mountains jersey, weighting them heavily towards the winners of the four mountain-top finishes which include one on the Col du Galibier, at 2,645m the highest stage finish in Tour history. Celebrating the 100th anniversary of the first Alpine stage, the final five days include three tough stages through the Alps including the first finish at l'Alpe d'Huez since 2008.

The Tour route presentation ceremony in Paris today appeared to skirt round the question of whether Alberto Contador will be confirmed as this year's winner after traces of the anabolic agent clenbuterol was found in his urine. The case is being investigated by the International Cycling Union and World Anti Doping Agency after the Spaniard claimed the positive test was due to eating contaminated steak. The ICU president, Pat MacQuaid, said that, if the meat explanation stands up, Contador will be cleared. But he added there is no indication yet as to how soon the Contador question will be resolved. The Spaniard was not in William Hill's list of odds for the 2011 race, with the bookmaker favouring the Luxembourger Andy Schleck with Bradley Wiggins at 40‑1.